The present invention relates to the field of life rafts for personnel who exit an aircraft in an emergency situation over a body of water. More specifically, the invention relates to inflatable life rafts that are inflated by pressurized gases stored in gas cylinders which are actuated to release their stored gases to the inflatable rafts. The invention especially relates to an inflatable encapsulating life raft system for use by aviators who eject from an aircraft.
Two-section life rafts which encapsulate a person and protect the person from the water after escape from a ship in an emergency situation are known and are disclosed in U. S. Pat. Nos. 4,187,570 and 4,355,987. A main flotation section provides primary flotation for the user, and an encapsulation section provides additional protection to the user from the water. With such known life rafts, both the main flotation section and the encapsulating section inflate simultaneously without giving the person an option to selectively inflate the main section without inflating the encapsulating section.
More specifically with respect to U. S. Pat. Nos. 4,355,987, an inflatable life raft having two separate pressurized gas sources and two separate inflatable sections is disclosed. The two separate inflatable sections serve a safety measure providing redundancy in case one of the inflatable sections is incapable of remaining inflated due to the presence of a hole or ruptured seam or the like. An important consideration in the design of the life raft disclosed in said patent is the provision of an actuation mechanism that guarantees that both sections of the life raft are actuated. The actuation mechanism in said patent does not provide for selective inflation of just one raft section or, alternatively, both raft sections at separate times at the choosing of the personnel using the raft.
Such known encapsulating life raft systems are not suitable for use by an aviator who ditches his aircraft in a body of water because an aviator needs to have the option of inflating only the main section first and then later inflating the encapsulating section after the aviator has climbed out of the water into the main section.
More specifically with respect to an aviator, if an ejection seat is ejected from the aircraft at a sufficient altitude to allow time to deploy a liferaft after deployment of a parachute, then both inflatable sections can be automatically inflated during parachute descent. During parachute descent, the aviator is secured in close proximity to the main flotation section; and the main flotation section is oriented with respect to the aviator to deploy behind the aviator during descent. During parachute descent, the encapsulating section deploys in front of the aviator so that when the aviator reaches the water from a parachute descent, he is encapsulated by the two sections of the system.
However, if the aviator ejects from the aircraft at an altitude that is too low to deploy the raft during parachute descent or if the aviator ditches the aircraft in the water and then leaves the aircraft, then inflation of the raft should be delayed until entry of the aviator into the water, and the kit containing the raft is detached from the aviator. More specifically, when the aviator enters the water, he would detach the raft container from his body and preferably first inflate the main flotation section. Then the aviator would climb into or board the main flotation section. Finally, once in the main flotation section, the aviator would then inflate the encapsulating section. Furthermore, the aviator should be able to decide when to bring about inflation of the raft sections independently. It would be difficult for the aviator to board a previously fully deployed encapsulating life raft system while the aviator is outside the raft in the water. Therefore, when the aviator does not deploy the raft during parachute descent, the aviator, when in water, should be able to inflate the main flotation section and inflate the encapsulating section independently of one another. For inwater deployment, the aviator should be able to manually actuate inflation of the main section and independently manually actuate the encapsulating section if desired.